Bug#703468: [3.2.35-2 -> 3.2.39-1 regression] fails to boot on apple iMac

[Geoff Crompton <geoffc@trinity.unimelb.edu.au>]

On 03/04/13 09:30, Jonathan Nieder wrote:
> Geoff Crompton wrote:
>
> > I had been considering building a kernel for each patch where the kernel
> > only includes that one patch. But with 17 patches, that seems like a lot
> > of kernels to test (for me anyway). So I've further whittled that down
> > by looking for patches that mention 'backport':
> >
> > geoffc@hulk:~/debs/linux-3.2.39$ cat ../i915_bug_patch_shortlist | xargs
> > grep -li backport
> > debian/patches/bugfix/all/i915-ensure-that-VGA-plane-is-disabled.patch
> > debian/patches/bugfix/x86/drm-i915-add-quirk_invert_brightness-for-ncr-machine.patch
> > debian/patches/bugfix/x86/drm-i915-Close-race-between-processing-unpin-task-an.patch
> > debian/patches/bugfix/x86/drm-i915-Disable-AsyncFlip-performance-optimisations.patch
> > debian/patches/bugfix/x86/drm-i915-dump-UTS_RELEASE-into-the-error_state.patch
> > debian/patches/bugfix/x86/drm-i915-GFX_MODE-Flush-TLB-Invalidate-Mode-must-be-.patch
> > debian/patches/bugfix/x86/drm-i915-kick-any-firmware-framebuffers-before-claim.patch
> > debian/patches/bugfix/x86/drm-i915-Only-increment-the-user-pin-count-after-suc.patch
> >
> > For these 8 patches I'll attempt to build packages that only include a
> > single patch from this short list, and see if one of those kernels
> > crashes. I don't have access to the machine that I've seen the bug on
> > until next week.
>
> Unfortunately I don't think the patches are independent.
>
> If you can find a way to bisect among them to see which introduces the
> problem, that would be great, but please also do test the 3.8.y kernel
> from experimental so we can get upstream help.
>
> Thanks again and sorry for the trouble,
> Jonathan

I can confirm the patches are not independant. I found 
bugfix/x86/drm-i915-Only-kick-out-vesafb-if-we-takeover-the-fbc.patch 
didn't apply if the above patches weren't included (because I'd 
commented them in the series file).

But I didn't get any further along that line of development. Instead I 
downloaded linux_3.8.5-1~experimental.1.dsc (and related) and tried to 
build that on my wheezy box. The build failed after a long time, but 
well after it had successfully built 
linux-image-3.8-trunk-amd64_3.8.5-1~gc70.1_amd64.deb. So I tried to 
install that (and found I also had to download and compile the 
initramfs-tools 0.110 package).

But now I'm running the 3.8.5 kernel successfully. So this bug is not 
present in a 3.8.5 kernel.

I guess given Jonathans comments on 2013-04-02 I should keep trying to 
build a 3.2.39 package without some selection of the above patches (and 
whatever else) to see if that does work, and then try adding back in 
patches until it fails.

Cheers,
Geoff